There are known railway wheels having disks in the form of a shell made up of a system of conjugating shells of flat, conical or curvilinear configuration. By varying the number of conjugating shells, their mutual positioning, and changing the angle of inclination of the median longitudinal axis of the disk configuration it is possible to increase the fatigue and dynamic strength of the wheels. Therewith, taken into account are the most important stresses and their combinations, such as:
against vertical forces acting in the plane of the rolling circle;
against side pressure of the rail on the rim ridge;
against a combination of these forces;
against non-uniform heating of the wheel due to the action of disk or block brakes.
A wheel construction that has found a wide application includes a wheel rim and a hub conjugating with a disk interposed therebetween, the medium longitudinal axis of the disk having the form of an inclined straight line, the disk having rectilinear generating lines conjugating with the configurations of the rim and hub by radius curves, conjugation at the outer side of the rim and at the inner side at the hub being effected by two interlinked radius curves of reverse curvature.
Among disadvantages of this wheel are:
high vertical and axial rigidity of the disk;
substantial residual stresses in transition zones between the disk and hub, and between the disk and rim;
high alternate stresses in the transition zones during operation;
a tendence of the hub to axially displace relative to the initial position in the course of prolonged braking;
manufacturing difficulties during stamping and bending.
Improvement of the wheels of the aforedescribed construction is impossible due to the fact that a higher fatigue and dynamic strength can be attained only by reinforcing transition zones between the disk and rim and between the disk and hub, which results in a higher rigidity of the wheel to aggravate the above disadvantages accompanied by more metal required for the wheel fabrication.
There is known a railway wheel (cf., SU, A, 1,109,324) comprising a rim and a hub conjugating with a disk interposed therebetween, the median longitudinal axis of the disk configuration being made up of rectilinear portions vertical at the side of the rim and inclined at the side of the hub, and a curcilinear portion disposed between the rectilinear portions and made up of two radius curves of reverse curvature, the curvilinear generating lines of the disk conjugating with the configurations of the rim and hub by radius curves, whereas areas defined by dissecting the disk by axial cylindrical surfaces being equidimensional, and the median longitudinal axis of the configuration of the disk is offset at the hub relative to the median longitudinal axis of the configuration of the hub toward the inner side of the wheel.
However, this wheel is also not free of some inherent disadvantages. Among them are substantial radial rigidity and residual stresses, relatively high tangential and radial stresses in the transition zones and, most disadvantageous, very highly stressed state of the disk during prolonged braking.